The present invention is directed to a tool for pulling off a rotor of a motor or a fan from a shaft. In U.S. Pat. No. 4,077,103 Kelley, which is incorporated by reference herein, there is disclosed such a tool for pulling off a rotor of a motor or a fan from a shaft. The tool includes an elongated, rotatable screw that is partially threaded in a hollow housing. The end of the elongated screw can be made to protrude from the end of the housing by rotating the screw in a first direction. By causing the end of the screw to protrude from the housing, the end may be brought into abutting engagement with the end of a shaft on which is mounted a rotor of a squirrel-cage motor, for example, or a fan. The housing is provided with means for securing the housing to either the rotor of a motor or to a fan, whereby, after abutting the end of the elongated screw against the end of the shaft, the screw is rotated causing the housing, with the securing means, to be translated along the screw, in a direction away from the shaft, which housing thereby carries along with it the rotor of the motor or the fan on the shaft to which the securing means had been applied. The securing means takes the form of a plurality of rotatable gripping bolts that are used for gripping the outer surface of a rotor of a motor, or the like, while, for removing a fan, or the like, from a shaft, a plurality of hooked arms are provided with an end of each hooked arm being removably received in a hole of the housing, with the other end "hooking" a rear surface-portion of the fan, whereby the respective rotor or fan, or the like, may be pulled off the shaft according to the method above-described. However, the hooked arms of this patent suffer from the serious disadvantage of falling out from their insertion-hole in the housing. Thus, the tool of the patent is also provided with retaining clips for holding the hooked arms in place, so they do not fall out and become lost, and so they do not interfere with the use of the securing bolts when pulling off a rotor of a motor, or the like, from a shaft. However, these retaining clips have not been found to be practicable in use, and have been ineffective in preventing the hooked arms from falling out and from interfering with the securing bolts for a rotor of a motor. In addition, the shape of the housing in the tool of the patent is square-shaped with the holes formed in the housing for receiving the ends of the hooked arms being provided in two, adjacent pairs, where one pair of holes is formed in one lateral surface face of the housing, and the other pair of holes in the opposite surface face of the housing. This arrangement fixes the manner in which the hooked arms are arranged with respect to the housing, which is a severe detriment to the use of the tool, since not all fans are provided with the same number of vanes nor with vanes of the same angular extent. Thus, where the hooked arms may be perfectly suited for a fan with four blades, the tool can only be used with difficulty for fans having more or less than four vanes, or a fan having vanes of considerably different angular extent.